Reliability Report - Phase 15

The rapid adoption of GaN devices in many diverse applications calls for continued accumulation of reliability statistics and research into the fundamental physics of failure in GaN devices, including integrated circuits (ICs). It is also necessary to look for information from real-world experience that either confirms the laboratory-derived data or opens new questions about mission robustness. This Phase 15 Reliability Report documents continued work using test-to-fail methodology and adds specific reliability metrics and predictions for solar optimizers, lidar sensors, and DC-DC converters.

Ricardo Garcia, Siddhesh Gajare, Ph.D., Angel Espinoza, Max Zafrani, Alejandro Pozo, Ph.D., Shengke Zhang, Ph.D.,

What is Covered in This Report:

  • SECTION 1: VOLTAGE/TEMPERATURE STRESS ON THE GATE
  • SECTION 2: VOLTAGE/TEMPERATURE STRESS ON THE DRAIN
    • 2.1 Physics-Based Dynamic RDS(on) and Lifetime Models
    • 2.2 Effect of Switching Frequency and Switching Current
    • 2.3 Impact of Higher Stress Voltage
    • 2.4 Conclusions for Physics-Based Dynamic RDS(on) Model
  • SECTION 3: SAFE OPERATING AREA
  • SECTION 4: SHORT-CIRCUIT ROBUSTNESS TESTING
  • SECTION 5: MECHANICAL STRESS
    • 5.1 Die Shear Test
    • 5.2 Backside Pressure Test
    • 5.3 Bending Force Test
  • SECTION 6: THERMO-MECHANICAL STRESS
    • 6.1 Criteria for Choosing a Suitable Underfill
    • 6.2 Underfill Study under Temperature Cycling
    • 6.3 Intermittent Operating Life Study
    • 6.4 Guidelines for Choosing Underfill
  • SECTION 7: RELIABILITY TEST RESULTS FOR GaN-ON-Si LASER DRIVERS
    • 7.1 Long-Term Stability Under High Current Pulses
    • 7.2 Monolithic GaN-on-Si Laser Driver ICs
    • 7.2.1 Qualification Test Overview
    • 7.2.2 Test-to-Fail Methodologies
    • 7.2.3 Key Stressors of eToF Laser Driver IC for Lidar Application
    • 7.2.4 VDD , Logic Supply Voltage
    • 7.2.5 VD , Laser Drive Voltage
    • 7.2.6 Operating Frequency
  • SECTION 8: USING TEST-TO-FAIL METHODOLOGY TO ACCURATELY PREDICT
    HOW eGaN DEVICES CAN LAST MORE THAN 25 YEARS IN SOLAR APPLICATION

    • 8.1 Gate Stress
    • 8.2 Drain Stress
    • 8.3 Thermo-Mechanical Stress
    • 8.4 Cosmic Rays
  • SECTION 9: DC-DC CONVERTER
    • 9.1 Current-Dependent Hot Electron Trapping Model
    • 9.2 48 V–12 V LLC Synchronous Rectifier
    • 9.2.1 40 V GaN Transistors – Cases 1 and 2
    • 9.2.2 30 V GaN Transistors – Cases 3 and 4
    • 9.3 48 V–12 V Buck Converter
    • 9.3.1 Low-Side GaN Transistor
    • 9.3.2 High-Side GaN Transistor
    • 9.4 Summary of Applying the Model to Important Real-World Use Cases
  • SECTION 10. SUMMARY
  • REFERENCES